However, existing classical byzantine fault-tolerant consensus protocols scale poorly with the number of participants[1]}, [2]}. This limitation stems from the large number of messages that need to be received, sent, and processed by a single process to reach consensus. For instance, the well-known PBFT protocol[3]} organizes participants in a clique resulting in a quadratic message complexity. More recent algorithms, such as HotStuff[4]}, organize participants in a star topology, where the leader sends/collects information directly to/from all other participants, which reduces the message complexity but not the load on the coordinator, that still has to receive and validate votes from all other processes. These designs are, therefore, inherently non-scalable.
